Vintage Dirt Bike Q & A

I picked up this 78 CR125 with a T&M swing arm and DG head. BUT the thing has 2 plugs and the center fin on the rear is gone. Did someone do this or did they make a different head fit this bike or DG get bored 30 years ago and drill an extra plug hole? Any knowledge would be great. Bike runs great.

JR

It's a 17 fin. MT125 head? I can't find anything DG for a MT125 except a pipe. Milled CR125 head?

I have never heard of an mt dg head only cr heads that were modified to work with the mt. I dont know about the 125 but the 250 heads had to have a fin or two shaved off the side to allow room for the uppipe. I have a dg bigfin head on my mt250 but I used a down pipe cause I wasnt about to ruin a nice dg head. I would guess the two holes are for two plugs cause I cant imagine anyone would need a compresion release on a 125.

It also looks like the rear fin was removed so someone could drill another hole in the head for a spare plug, maybe it was in the way of the drill or somthing. I have seen people use two plugs before, the second is there incase the first fouls. I have just always brought tools and a spare plug with me. Dg heads I thought were for racers so I really doubt dg would add two plugs to the head as a racer wont need it. If you gotta stop and unplug your spark plug and plug in the other one I think the race is lost.

Yeah I think someone got bored and wanted to practice their milling skills on a DG head. I'll pop off the cylinder to see if it's ported too. If they went to all that trouble, hopefully they ported the cylinder too. Guess it might go on ebay with a DG pipe as a package deal.